Red Flag Warning 13, NWS Missoula, MT

383 
WWUS85 KMSO 070257
RFWMSO

URGENT - FIRE WEATHER MESSAGE
National Weather Service Missoula MT
857 PM MDT Sun Sep 6 2026

MTZ111-070400-
/O.CAN.KMSO.FW.W.0013.000000T0000Z-260907T0300Z/
East Beaverhead-
857 PM MDT Sun Sep 6 2026

...RED FLAG WARNING IS CANCELLED...

$$

Area Forecast Discussion
National Weather Service Missoula MT
344 AM MDT Sat Sep 5 2026

.DISCUSSION...

KEY MESSAGES:

-  Some stronger showers and storms possible this afternoon.

-  Widespread showers increasing Sunday into Monday with
   seasonably cool temperatures persisting into early next week.

-  Gradual drying trend develops mid-week alongside morning
   valley fog.

Shower activity will wane this morning giving way to partial
afternoon clearing. Solar heating will generate weak to modest
instability, supporting spotty afternoon showers and thunderstorms
capable of brief heavy rainfall, lightning, hail, and erratic
convective outflow gusts of 25 to 45 mph. Persistent moderate
showers will continue tonight across western Montana.

An upper-level closed low will track directly across the Northern
Rockies Sunday through Monday before departing Saskatchewan-bound
by Tuesday. Dynamic forcing and rich moisture advection will
produce widespread, soaking rainfall. Probabilities for rainfall
exceeding 0.50 inches are very high between Sunday morning and
Tuesday morning reaching 80 to 90+ percent across West- Central
and Northwest Montana, 60 to 80+ percent across North-Central
Idaho, and as low as 60 percent for Southwest Montana. A 50
percent chance exists for total rainfall exceeding 2.00 inches
from the Flathead Lake region extending north and east across the
Glacier Region. Cold air entrainment aloft will lower snow levels,
producing some mountain snow accumulations above 9,000 feet.

The forecast becomes a bit uncertain toward the middle part of
next week, but what we know so far is:
The closed low exits to the northeast on Tuesday, allowing high
pressure to build over the region into the middle of next week.
This pattern will bring a drying trend with moderating
temperatures, though lingering boundary-layer moisture will
continue to support overnight and early morning valley fog and
low stratus.

&&

.AVIATION...Morning showers will decrease in coverage and give way
to partly cloudy skies across the region. Scattered showers and
thunderstorms are possible across western Montana and could impact
KMSO and KHRF. Expect generally weak winds at the terminals.
Persistent light to moderate rain showers are expected overnight
through Sunday morning impacting KGPI, KMSO and KHRF. More
scattered showers and thunderstorms are possible on Sunday.
&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&